Coated plastic articles



May 27, 1958 J. PINSKY ETAL COATED PLASTIC ARTICLES Filed Aug. 13, 1957 INVENTORS AZf/Efldalcozzs mdc/,Shiva BY a@ Jules Pznslgy fl/Iliff l l l United States Patent O COATED PLASTIC ARTICLES Jules Pinsky, West Hartford, Albert E. Adakonis, East Hartford, and Alvin R. Nielsen, Hartford, Conn., assignors to Plax Corporation, Bloomiield, Coun., a corporation of Delaware 'Application August 13, 1957, Serial No. 678,000

20 Claims. (Cl. 21S- 1) cifically, the invention is directed to plastic articles, such as polyethylene containers and bottles, a surface of which is modied by application of a coating thereto to prevent or reduce the rate of permeation of the synthetic resin material Vby many of the commonly encountered iiuids,

particularly organic liquids.

Synthetic resin containers and bottles as, for example, polyethylene bottles, have become Widely popular as a packaging means for various liquids such as deodorants, hair preparations, cosmetic preparations, medicinal preparations, and the like. 'In particular, polyethylene has been and is widely used in the production of squeeze bottles for the distribution of such preparations in that it is relatively inert, has the necessary exibility to function as a squeeze bottle, and `can be easily fabricated in quantity at a reasonable cost. Unmodified polyethylene is entirely satisfactory for a wide variety of materials. However, polyethylene and other synthetic resins which are useable as containers are permeable to many organic liquids, including a large number of conventional organic solvents which are widely used in iluid preparations for which the polyethylene bottle or container is highly desirable. Representative chemicals, for example, which permeate with various degrees of rapidity through polyethylene at room temperature, include the straight chain hydrocarbons, the aromatic hydrocarbons, esters, ketones, and various other non-polar uids. Consequently, because of this high permeability characteristic of polyethylene and other synthetic resin materials from which containers'are desirably fabricated, the use of these materials has of necessity been restricted to those products to which the resin is substantially impermeable. ene with respectto certain of these chemicals has 'resulted in polyethylene bottles-being rejected 'for use in applications Where, due to itsl ilexibility and ease of `fabrication, it might otherwise be employed to great advantage.

It has previously been suggested that polyethylene bottles be lined with such materials as polyvinyl alcohol, polyvinyl chloride and copolymers of polyvinyl chioride and polyvinyl acetate to obtain an oil resistant lm which will resist permeation by oily materials. While such liners have been moderately successful, there is currently no known liner material which will form a ilexible coating on a polyethylene surface and which will resist -permeation by a .wide variety of Aorganicriuids -such as The permeable characteristics of'polyethyl- 2,836,319 Patented May 27, 1958 which is characterized by enhanced resistance to permeation'by a variety of uids.

It is another object of this invention to provide a container or bottle formed from a synthetic resin, a surface of which carries a ilexible coating which will prevent permeation of the resinous container structure by a variety of commonly employed organic fluids.

it is an additional object of this invention to provide a polyethylene bottle having a ilexible, resinous coating on thevinterior and/ or exterior surface thereof which is characterized by enhanced resistance to permeation by a variety of organic tiuids, particularly the common hydrocarbon solvents.

It is another object of the present invention to provide a polyethylene bottle having a ilexible, adherent, synthetic resin coating which is substantially impermeable to many organic Fluids capable of substantially permeating the polyethylene bottle walls in the absence of such coating.

A further object of the invention is a lined container or bottle formed from a synthetic resin, preferably polyethylene, which'is highly flexible and useable in squeeze bottle applications without deleterious effect on the container or bottle, to retain organic fluids without objectionable loss due to their permeationof the container or bottle.

In co-pending application Serial No. 574,383, filed March 28, 195,6, and of which the present application is a continuation-in-part, it is disclosed that excellent resistance to .permeation of synthetic resinous containers by a variety of commonly employed organic fluids Amay be obtained by lining and/'or coating the surface thereof Witha cured epoxy resin. Containers, and particularly polyethylene bottles coated or lined with cured epoxy resin compositions, have proved highly successful as containers for such organic fluids as carbontetrachloride, toluene, ethyl acetate, acetone, benzene, oils and compositions containing such materials. While these coated or lined containers have generally exhibited requisite flexibility for many commercial applications, the increased use of squeeze bottles, especially as dispensers for cosmetics, medicants, air fresheners, cleaning iluids, household lubricants, and the like, make it desirable to employ a liner characterized by maximum flexibility without adversely aliecting the resistance of the lined container to iluid permeation.

In accordance with the present invention, it has now been discovered that liners and coatings of enhanced exibility and having excellent resistance to permeation by a wide variety of organic uids may be obtained by a particular combination of epoxy resins with a hardener.

Generally described, the present invention comprises a synthetic resin article having a surface characterized by enhanced resistance to permeation by fluids, said surface having a coating of the cured mixture of:

said Aand lBbeing admixed in a ratio of between about 1:1 and. about 50:1. .It has been found that if the limiting `rangesnin =`A andthe limiting ratiosV between A and'B are not observed'the-fdesired high flexibility and low perm/cation characteristics are not obtained. Prefer- ,a'bjly aratio of between 5:1 and 15:1 will be employed.

normally hydrophobic materials in accordance with'the in- In aYV more specific embodiment the invention comprises a synthetic resinous container, a surface of which has a coating of the cured epoxy resin composition of the invention. InV its preferredcmbodiment the invention comprises a polyethylene bottle, a surface of which has a coating of the cured epoxy resin composition of the invention.

Any of the conventional hardeners may be employed Vto cure the epoxy resin composition of the invention. Epoxy resins may be Vreadily hardened or cured to an insoluble, infusible staterby reaction of the epoxy and hydroxyl groups with cross-linking agents including diamines or polyamines, such as metaphenylene diamine, diethylene triamine and the polyethylene polyamines; diisocyanates', such as methylenerbis-(Lt phenyl) isocyanate;

" 2,ase,a19

ndia1dehydes,`such`r as glyoxal; dimercaptans; and amides and polyamides, such as those disclosed in U. S. Patent No. 2,705,223. Preferably, the epoxyvresin mixture of the invention will be cured by a hardener admixed therewith in a ratio between about 1:1 and about 10:1 by

weight. Particularly desirable curable mixtures will contain epoxide and hardener in a ratio of between about 4:1 and about 6:1 by weight. The coatings applied to the synthetic resin surfaces in accordance with this invention; are the cured lor hardened epoxy resins obtained by A'reaction ofthe particular admixture of peroxides of the inventionwith a hardener or cross-linking agent for epoxy. resins. Y

It is oftenV desirable to chemically pretreat the plastic A' substrate to render the material more receptiveY to polar Vcompounds and thus promote enhanced adherence .of the coating orrlining' materiali. In U. S. Reissue PatentgNo. 24,062 to Horton, it is disclosed that improved adherence of polar compounds to polyethylene may be'elejcted by treating the surface to be printed, lined or coated With a solution of sulfuric acid and a dichrornate. U. S. Patents 2,715,075, 2,715,076 and 2,715,077 to'Wolinski disclose that desired surface modification may 'be obtained by treat- Vment with ozone, nitrous oxide or mixtures of the two.

Suitable surface modification also may be obtained by flame treating the surface to be printed, coated or lined, such Vas shown in U. S. Patents 2,632,921 and 2,704,382 to VVKreidl. All of these treatments involve the oxidation ofy beV rendered more receptive to polar compounds by sulfo-Y Vnation or chlorination.

Thus the degree of adherency of the coatings or liners to the articles or containers of the invention will vary,

depending on the nature of the substrate being coated;

The coating applied to untreated polyethylene and lother vention is adherent in the sense that the coating'- clings to sistan'ce to permeation lof the coated or lined surface. Where for reasons of optimum performance and/or ap- The epoxy resin of Ythe'invention is preferably applied to (A Vreaction,prodiinct:

specific embodiments thereof. For purposes'of' brevity i Vivthe substrate when applied and does not separate during Anormal usage to a degree deleteriously aiecting the recomposition of the invention;

solved in a suitable solvent such as toluene, methyl ethyl and about ventional techniques, such as by spraying, or manually by at least partially filling the bottleV followed by suitable Y manipulative and draining steps to insure the application of an even coating to the interior surface. If the coating is applied to the exterior surface of the article, it need simply be immersed in a bath of the coating material and allowed to drain.` Exterior coatings also may be appliedY by spraying techniques. Where the coatings of the invention are applied -by spray techniques, it isY especially desirable to chemically pretreat the substrate and'thus insure enhanced continuity and adhesion of the coating.

The cured coating or lining is produced in situ by subjecting the coated article to a curing temperature for a period of time necessary to produce the desired chemical reaction. Desirably, the'coating will be cured at a temperature of -220" F. for a period of at least a half hour. Shorter periods of time may obviously be employed with higher 'curing temperatures'. The curing timeaud temperature will also -be varied by the amount and type of catalyst or hardening agentemployed. If desired, the lined or coated objects may be allowed to stand for an extended period, e. g., twenty-four. to seventy-two hours at room temperature prior to being cured at higher temperature, thus reducing the time required for the advanced temperature curi'ngoperation.V The softening'point of the plastic being coated generally constitutes the upper limit of the curing temperature and for unmodified I this upper limitY is about 220F. Y

In the accompanying drawing illustrative embodiments of the invention are presented.V Y

Figure 1 is an elevational view of a conventional Boston Round polyethylene bottle 10 which has not been modified in accordance` With the invention; C Figure 2 isa sectional View of a similar polyethylene bottle 10 having a continu-ous external coating 11 of the Vcured epoxy resin composition of the invention;

Figure 3 is a sectional Vview of a similar polyethylene bottle 10 having a continuous internal lining 12 of Ythe cured epoxy resin composition `of the invention; and

Figure 4 is a sectional View of a similar polyethylenev VHaving generally'describe'd the invention, the following examples are presented for purposes of illustrating various in the examples, the epoxy resins employed in accordance with the invention will be referred to as Epoxy Resin A or B Aas identified below.

CH'. o

1 Y 1H i 'lo' Y Y (l) 65% CH2 CHCHQOOOOCHzCHCHzOCHQC \CH: Y

f Y Hi Y Y (A reaction product of epichlorhydrin, p,p'dihydroxy diphenyl dimethyl methane and epihydric alcohol) (A) om roxy phenyl, kp-lrydrorxky-Vo-v(p-hydroxy benzyl)r` phenyl the surface to be lined or coated in an uncured state, dismethane) V(B) I Y "fr" 'Y Y 't n ,Y C'HaY 'Y f Y ?Hi` Y Y (')H A, ',.CHS 2 '/O\i i o oHoHo VoV oon non'o o" Y .f :t @Q3 1 ,Opo @H1 phenyl dimethyl methane) polyethylene the cured epoxypr'esin A.

/O\ OV v35% om cHoHtoOh-AQocmc/H \crr,` Y

. C a i Similarly, the preferredhardener or cross-linking agent employed in the examples also will be referred to as hardener C. It will be undfyfstood, however, that other hardeners or cross-linking agents as referred to hereinabove and as known to the art as hardeners or crosslinking agents for epoxide resins may be substituted for hardener C. Hardener C is identified below.

(C) OH CH3 ,naaste l Nnf-oH-onqNnomoHiNnomoncmoOh-Oo cHiononiNHontoniNHcHrcHiNn,

The inner surfaces of all of the lined polyethylene bottles employed in the examples were treated prior to lining to oxidize the surfaces and thus render them more receptive to polar compounds. in all cases the lined -bottlesv prepared as in the examples could Vbe flexed repeatedly as in squeeze-bottle operation without deleterious eiiect on the liner or the permeability characteristics of the bottle. Unless otherwise indicated, all parts are .by weight.

EmPLE I Resin A and resin B were admixed in a ratio of :1. Four parts of the admixture of A and B and one part of hardener C were then adrnr'xed and diluted with methyl ethyl ketone to a solids content of 60%. The interior surfaces of 4-ounce Boston Round polyethylene bottles were manually lined by the pour-in, pour-out technique and the -liners were cured at 164 F. for two-hours and had an average weight or" 0.57 gram. The lined bottles and an equal number of unlined control bottles were filled with a commercial cigarette lighter fluid which heretofore had been found to be an extremely fast permeator of unlined polyethylene bottles. Part of the bottles in accordance with the invention and part of the unlined control bottles were stored at 73 F. for twenty-eight days and the remainder of the two groups of bottles were stored at 120 F. for a period of twenty-eight days. On the basis of the difference in weight before and after storage, it was determined by calculation that the percent weight loss per year at 73 F. for the linedbottles was 1% `whilethe percent weight loss per year of the unlined` bottles was 402%. For the bottles stored at 120 F. the calculated percent weight loss per year for the lined bottles was 2.4% and for the unlined controls was 1006.0%.

EXAMPLE Il Additional 4-ounce Boston Round polyethylene bottles lined in accordance with the procedure of Example I were prepared. In this instance the liners were cured at 190 F. for one hour and had an average -weight of 0.6841 gram. The lined bottles and unlined control bottles were iilled with a commercial electrical joint compound containing 50% petrolatum and, as active ingredients, included amino compounds and luorides. The lined and unlined bottles were stored at 73 F. and 120 F. as in Example l. The calculated annual weight loss of the bottles stored at 73 F. was 4.57% forthe unlined control bottles but there was no discernable weight loss for the lined bottles. In the bottles stored at 120 F. the calculated annual weight loss for the unlined control bottles was 37.9% but only 2.13% forthe lined bottles. The unlined bottles stored at both 73 and 120 F. had collapsed, while no collapse whatsoever was noted in the vcase of the lined bottles at either storage temperature. Y

EXAMPLE 1H Resin A and resin B were admixed in a ratio of 110:1. Eight parts of the admixture of A and B were then admixed with one part of hardencr C and the admixture lled with hexane, toluene, ethyl acetate and carbon tetrachloride and stored at 73 F. for 124 days. The average weight loss in grams per day of the lined bottles as compared to unlined control bottles is shown below.

Test Fluid Unlined Lined Bottles Bottles n-Hexane 2.2 0. 0150 Toluene 2. 79 0. 0106 Ethyl Acetate 0. 095 0. 0016 Carb on Tetrachlorlde 3. 49 0. 023

EXAMPLE IV A lining solution was prepared from 35.5 parts of resin A, 3.5 parts of resin B and 9.7 Vparts of hardener C. The mixture was diluted with Vmethyl ethyl ketone to a solids content of 65%, and 4-ounce Boston Round polyethylene bottles were spray lined on a conventional Paasche spraying machine. A portion of the bottles were single sprayed and the remainder were double sprayed. The double sprayed bottles were not cured between sprays. Both vthe single sprayed and double sprayed bottles were cured for one hour at a temperature between F. and 210 F. The lined bottles were then filled with hexane, toluene, ethyl acetate and carbon tetrachloride and stored at 73 F. for twelve days. The results obtained in comparison with unlined control bottles are shown below.

Weight loss-grams per day per boztle Resin A and resin B were admixed in a ratio of10z1. Four parts of the admixture of resin A and resin BV were then admixed with one part of hardener C. The mixture was then dissolved in sufficient methyl ethyl ketone to provide a solids content of 65%. Four-ounce Boston Round polyethylene bottles were spray lined with the resulting solution as in Example IV and the lined bottles were cured at 200 F. for one hour. The lined bottles and unlined control bottles were then filled with a commercial tobacco spray containing 50% of a petroleum hydrocarbon solvent, the active insecticidal ingredients and an anionic emulsier. The lilled bottles were store at 73 F., 100 F. and 120 F. The weight loss and bottle appearance at the end of twenty-eight days is shown in the table below.

. Y v Calculated Y p Y Weight Appearance Bottle Identication and Temperature Loss Per of Bottles ear (Gms.)

Controls, 73 F 31. 85 Collapse. Controls, 100 F-.'- 99. 20 Do. Controls, 120 F- 161. 3 Do. Lined, 73 F. .504 Good. Lined, 100 F- 2. 78 Do. Lined, 120 F 6. 78 Do.

EXAMPLE v1Y Resin A and resin B were again admixed in a ratio of 10:1. Three and two tenths parts of this mixture were thenadmixed with one part of hardenerY C and diluted with methyl ethyl ketone to a solids `contentof 65%. Four-ounce Boston Round polyethylene bottles were manually lined by the pour-in, pour-out technique and the liners were cured one hour atk 200 F'. The cured liners averaged 0.392gram Vin weight. Several lined bottles Vwere filled with each of n-hexane,-toluene, ethyl acetate' and carbon tetrachloride and the filled bottles were stored at 73 F. for 156 days. The followingY aver;-

Vage daily weight losses were obtained at'. thirty days and 156 days as compared with the unlined controls.,V

Y Weight loss-grams per day per bottle VA8 characterizing the cured epoxiderliners or coatings inaccordance with the invention results from the admixture of a cured epoxide A containing as a constituent thereof an epoxide resin having .three reactive epoxy groups to the molecule with the uncured epoxide B which possessses only two reactive epoxide groups positioned at opposite ends-of a relatively long straight chain molecule. This particular combination when cured by ruse' of a conventional-hardener for epoxide resins appears to produceV a molecule having suicient cross-linking Vto give adequate barrier effect to reduce permeation by organic Y iluids but'atY the same time containingV suicient spacing between the cross-linked portions to produce the enhanced flexibility characterizing the compositionsrof the Test Fluid Unlined Days-4 156 Days- Y Lined Lined nnexane 2.2 Y 0.0000 'Y 0.0070 Toluene Y 2.79 v 0. 0093 Y Y 0.0085 Y Ethyl Acetate `0.095 0.0041 0.0035 Carbon Tetrachloride 3. 94 0. 0096. 0. 0134 EXAMPLE vrV i Resin A and resin Bewere again admixedin a ratio of Five and two tenths parts of this mixturewereV Y10:1. then admixed withone part of hardener C and -diluted with methyl ethyl ketone to a'solids content of'65%. Four-ounce Boston Round polyethylene bottles were manually lined by the pour-in, pour-out technique and Vthe liners were cured one hour at 200 The cured liners averaged 0.392 gram in weight.v Several lined bottles were filled with each of n-hexane, toluene, ethyl acetate and carbon tetrachloride and the lled bottles were stored at 73 F. for 153 days. The following aver age daily Weight losses were obtained at twenty-seven days and atrl'53 days as comparedwith the'unlined controls.

Weight loss-grams per day per bottle Y 'restrluid Uniined 27 mys-V 153 Days-V4 Y Lined"""'Lined containers forsuch materials vor compositionsV containing .containers and bottles may be satisfactorily employed as Y these inaterialsfwhen the containers are lined with a cured epoxy resin in accor-dance withthe :presentiin've'ntion.

Y "Whileit is not desired to be'boundpby the theory here expressed, it is believed that- 'the increased flexibility invention.

lt often is beneficial to irradiate the lining or coating solution during the curing procedure. Not onlyvk does irradiation accelerate the normal cross-linking reaction but often effects a graft polymerization whereby the epoxy and/or hardening agent is chemically; combined Y with the substrate, thusigreatlygenhancing theadherence ofthe coating or lining to the substrate. f Although in the examples particular emphasis has been placed on the popular polyethylene bottle, it is also within the scope of the invention that coatings .and/orlinings of the curedepoxy resin composition of the Vinvention be employed with other synthetic resinous articles which Yare permeableV to organic fluids such as carbon .Ytetraj chloride, hexane, acetone, benzene, toluene, and the like. The invention ris broadlyV applicable to plastic Varticlespr Ycontainers fabricated frornall types of therrnc'J-plasticv or thermo-'setting resins. More speciiically, vtheinven tion is applicable to articles or containers fabricated from such materials as polyethylene,:including conventional ture polyethylene, such asziegler polyethylene, i( poly-l v methylene'or polyethylene substantiallyvfree of branched Chains, polyethylene'terephthalate,V polytetrauo'rethylene,

nylon, acetate copolymers,V ethylene-polyvinyl acetate copolymers, coumarone resins; indene resinsyacetrylene polymers, including their halogenated derivatives; 'poly-f mers of olefin hydrocarbons other than ethylene; includ` ing polymers of; isop'rene, `butadiene and their homo- Y Alogues, and halogen-substituted derivativesthereofyoleiin-y sulfur dioxide resins; phenol-aldehyde resins; aldehyde resins; furfural resins; ketone resins; Yurea-fornnaldehyde v vtypefresins; including thiourea-formaldehyde, melamine formaldehyde,r and .dicyandiamidelformaldehyde.resins;

amine-aldehyde resins; sulfonamide-aldehyde resins; -nitro resins; resins from such'nitro'gen containing materials as hydrazine and related substances, pyrazoles, pyridine, quinoline, p yorrole, indole'and carbazole; condensation polyester resins, including resins obtained from polyhydric alcohols andY 'polybasic acids, and from hydroxyacids; Y j

polyamide resins and derivatives thereof; mixed fpoly'- Y ester-polyamide'resins; polyether resins; polyvinyl'ethers;

polyvinyl alcohols; polyvinyl esters;'rubber aridits Vderivatives; cellulose esters fand cellnlose'ethers. All ofthese Y Y v Aplastic materials may be used with any of the usual modi-VV fying agents including plasticizers, pigments, fillers, Ydyes and materials'which'combine chemically with the 'polymer l ingredients- VeitherY during formation of,Y the polymer or ,during'an after treatment. Thus, surfaces andc'on-y *Y Vtainers fabricated 'from'copolymers interpoly'm'ersV and mixtures of polymers maybe advantageouslyV renderedY less permeablevto'organic iluids by application ofaV coat- `ing or lining of a cured epoxy resin.A Y K Y Y As indicated, containers or bottles may, in'acordance "with the invention, becoated Qrlined on leither theY itx-f terior or exterior surfaces,orfbo'th..A Where the rproblem involved is merely the preventionof moisturegfiornenter` ing the product'tobe packaged `or' to prevent gases from the atmosphere from contacting the contents ofthe con- Y Y tainer, Van externalv impermeable coatingis. vsatisfactory..

"However, from the standpointof .theY permeationgof polyethylene and the so-called new type low tempera-V a liquid within a container outwardly through the container Walls, it is greatly preferred to employ an interior lining or coating. Moreover, with an external coating, an ingredient of the duid content may be essential, a1- though quantitatively small, and consequently such ingredient may be lost by absorption in the container wall even though the ingredient does not escape from the bottle itself. This latter situation is especially important where the containers are employed for skin lotions, perfumes, foods, liquors and the like, in which the essential oil fraction governing the perfume odor is relatively small. Accordingly, despite the proportionally greater diculty of applying a lining to the containers interior, the advantages of such an inner lining are such that it is preferred. In some instances it may be desirable to apply both an interior and exterior lining.

The mechanical methods rof applying the coating or lining to the container surfaces are well known t-o the art and do not constitute a part of the present invention. Specic details of the operation and functioning of spray coating units may be found in Paasche Patents 2,547,884, 2,059,706 and 2,069,844.

Since modifications of the disclosed invention will be apparent to those skilled in the art, it is intended that the invention be limited only by the scope of the appended claims.

What is claimed is:

1. A synthetic resinous article having a surface characterized by enhanced resistance to permeation by uids, said surface having a coating `of the cured mixture of: (A) an epoxy resin composition containing by weight from about 90% to about 10% of the reaction product of epichlorhydrin, p,p dihydroxy-diphenyldimethyl methane and epihydric alcohol and from about to about 90% of the reaction product of epichlorhydrin and dimethyl, p-hydroxyphenyl, p-hydroxy-o-(p-hydroxybenzyl) phenyl methane, and (B) the reaction product of epichlorhydrin and p,p'-dihydroxy-diphenyldimethyl methane; said A and B being admixed in a ratio of between about 1:1 and about 50:1.

2. An article according to claim 1 in which the epoxy resins are cured by a polyamine.

3. An article according to claim 1 in which the epoxy resins are cured by a polyamine admixed with the said resins in a ratio of between 1:1 and 1:10 by weight.

4. An article according to claim 1 in which the epoxy resins are cured by a bis-phenyl polyamine admixed with the said resins in a ratio of between 1:1 and 1:10 by weight.

5. A polyethylene container having a surface characterized by enhanced resistance to permeation by organic uids, said surface having a coating of the cured mixture of: (A) an epoxy resin composition containing by weight from about 90% to about 10% of the reaction product of epichlorhydrin, p,pdihydroxy-diphenyldimethyl methane and epihydric alcohol and from about 10% to about 90% of the reaction product of epichlorhydrin and dimethyl, p-hydroxyphenyl, p-hydroxy-o-(p-hydroxybenzyl)phenyl methane, and (B) the reaction product of epichlorhydrin and p,pdihydroxy-diphenyldimethyl methane; said A and B being admixed in a ratio of between about 1:1 and about 50:1.

6. A container according to claim 5 in which the epoxy resins are cured by a polyamine.

7. A container according to claim 5 in which the epoxy resins are cured by a polyamine admixed with the said resins in a ratio of between 1:1 and 1:10 by weight.

8. A container according to claim 5 in which the epoxy resins are cured by a bis-phenyl polyamine admixed with the said resins in a ratio of between 1:1 and 1:10 by weight.

9. A polyethylene bottle of increased resistance to permeation by organic iluids, at least one surface thereof having a coating of the cured mixture of: (A) an epoxy resin composition containing by weight from about to about 10% of the reaction` product of epichlorhydrin, p,pdihydroxy-diphenyldimethyl methane and epihydric alcohol and from about 10% to about 90% of the reaction product of epichlorhydrin and dimethyl, p-hydroxyphenyl, p-hydroxy-o-(p-hydroxybenzyl) phenyl methane, and (B) the reaction product of epichlorhydrin and p,p'dihydroxy-diphenyldimethyl methane; said A. and B being admixed in a ratio of between about 1:1 and about 50:1.

10. A bottle according to claim 9 in which the epoxy resins are cured by a polyamine.

11. A bottle according to claim 9 in which the epoxy resins are cured by a polyamine admixed with the said resins in a ratio of between 1:1 and 1:10 by weight.

12. A bottle according to claim 9 in which the epoxy resins are cured by a bis-phenyl polyamine admixed with the said resins in a ratio of between 1:1 and 1:10 by weight.

13. A bottle according to claim 9 in which the coating is on the exterior surface.

14. A bottle according to claim 9 in which the coating is on the interior surface.

15. A polyethylene container of increased resistance to permeation by organic fluids comprising a chemically pretreated surface receptive to polar compounds, said surface having a strongly adherent coating of the cured mixture of: (A) an epoxy resin composition containing by weight from about 90% to about 10% of the reaction product of epichlorhydrin, p,pdihydroxy-diphenyldimethyl methane and epihydric alcohol and from about 10% to about 90% of the reaction product of epichlorhydrin and dimethyl, p-hydroxyphenyl, p-hydroxy-o-(p-hydroxybenzyl) phenyl methane, and (B) the reaction product of epichlorhydn'n and p,pdihydroxy diphenyldimethyl methane; said A and B being admixed in a ratio of between about 111 and about 50:1.

16. A container according to claim 15 in which the epoxy resins are cured by a polyamine.

17. A container according to claim 15 in which the epoxy resins are cured by a polyamine admixed with the said resins in a ratio of between 1:1 and 1:10 by weight.

18. A container according to claim 15 in which the epoxy resins are cured by a bis-phenyl polyamine admixed with the said resins in a ratio of between 1:1 and 1:10 by weight.

19. A container according to claim 15 in which the coating is on the exterior surface.

20. A container according to claim 15 in which the coating is on the interior surface.

Castan June 29, 1948 2,491,947 Bardash Dec. 20, 1949 2,811,468 Joire Oct. 29, 1957 UNITED STATES PATENT OFFICE Certieate Patent No. 2,886,319 Patented May 27, 1958 Jules Iinsky, Albert Adakonis, and Alvin R. Nielsen Application lia-ving been inade by Jules Pinsky, Albert E. Adalonis, and Alvin It. Nielsen, the inventors named in the patent .above identified; and PlaX Corporation, Bloomfield, Connecticut, a corporation of Delaware, the assignee, for the issuance of a certificate under the provisions of Title 35, Section 256, of tlie VUnited States Code, deleting the naine of the said Albert E. Adakcnis as a joint inventor, .and a showing and proof of facts satisfying the requirements of the said section having been submitted, it is this 8rd day of December 1968, certified that the name of the said Albert E. Adakonis is liereby deleted from the said patent as a joint inventor with the said .Iules Pinsky and Alvin R. Nielsen.

EDWIN L. REYNOLDS, First Assistant Commissione?" of Patents.

UNITED STATES PATENT OFFICE Certificate Patent No. 2,836,319 Patented May 27, 1958 Jules Pinsky, Albert E. Adakonis, and Alvin R. Nielsen Application having been made by Jules Pinsky, Albert E. Adakonis, and Alvin R. Nielsen, the inventors named in the patent above identified; and Monsanto Company, a corporation of Delaware, the assignee, for the issuance of a certificate under the provisions of Title 35, Section 256, of the United States Code, deleting the name of the said Albert E. Adakonis .as a joint inventor, and a showing and proof of facts satisfying the requirements of the said section having been submitted, it is this 8th day of April 1969, certified that the name of the said Albert E. Ada-konis is hereby deleted from the said patent as a joint inventor with the said Jules Pinsky and Alvin R. Nielsen.

This certificate supersedes the certificate issued under 35 U.S.C. 256 on December 3, 1968.

[SEAL] EDT/VIN L. REYNOLDS, First Assistant Oomvnz'ssz'oner 0f Patents. 

5. POLYETHYLENE CONTAINER HAVING A SURFACE CHARACTERIZED BY ENHANCED RESISTANCE TO PERMEATION BY ORGANIC 